1. Field of the Invention
The present invention relates to a thermoplastic resin composition with excellent properties in heat resistance, transparency and weather durability. More particularly, the present invention concerns a thermoplastic resin composition in which the weather durability of the methacrylimide group-containing polymer is improved.
2. Description of the Prior Art
It is well known that the methacrylimide group-containing polymer is a thermoplastic resin with a high heat distortion or heat resistance temperature and a high degree of transparency (Japanese Patent Publication No. 38404/1985).
However, the methacrylimide group-containing resin polymer is not good enough in weather durability such as resistance to solar rays, wind and rain, and hot and cold, giving rise to deteriorations in transparency and appearance, which are extremely important problems in practical use.
In order to improve the weather durability of such methacrylimide group-containing polymers, an attempt has been made to add thereto a benzotriazole type ultraviolet ray absorbent. However, even this method fails to obtain a methacrylimide group-containing polymer which is comparable to methyl methacrylate resin which is a transparent and has the most excellent weather durability.
As a result of studies for improving the weather durability of the methacrylimide group-containing polymer, it has been found that a methacrylimide group-containing polymer composition with unexpectedly excellent weather durability can be obtained by adding a specific amount of a specific sort of an ultraviolet absorbent to the methacrylimide group-containing polymer.